Vehicle upholstery member having air bag door, and method and device for producing the same

ABSTRACT

A vehicle upholstery member having an invisible type air bag door formed with a break-scheduled line that is designed for easy measurement of depth or the like and that cannot be recognized from the front surface side; a method of producing the same; and a device for producing the same. In a vehicle upholstery member having a skin-equipped air bag door and in a method of producing the same, a portion of the back surface of the skin corresponding to the portion where the vehicle air bag is installed is formed with a break-scheduled line that is not so deep as to reach the surface of the skin and adapted to assume a substantially V-shaped groove shape when the skin is bent with its back surface convexed, and the depth of the break-scheduled line or the thickness of the remaining portion is measured, with the incision of the break-scheduled line opened. Further, a device for producing a vehicle upholstery member having such air bag door comprises a support base for substantially flatly mounting the skin thereon, a cutting blade for forming the break-scheduled line in the skin, and measuring means for measuring the depth of the break-scheduled line or the thickness of the remaining portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/JP03/07404, filed Jun. 11, 2003.

TECHNICAL FIELD

The present invention relates to a vehicle upholstery member having anair bag door, which is used in a steering wheal, an instrument panel, orthe like incorporating a vehicle air bag; a method of producing thesame; and a device for producing the same. More particularly, thepresent invention relates to a vehicle upholstery member having aninvisible type air bag door (hereinafter, which may be also simplyreferred to as a vehicle upholstery member) formed with abreak-scheduled line that is designed for easy measurement of the depththereof or the thickness of the remaining portion and that cannot berecognized from the front surface side; a method of producing the same;and a device for producing the same.

BACKGROUND ART

Heretofore, a steering wheel or an instrument panel provided integrallywith an air bag door for developing an air bag has possessed, on itssurface side, a vehicle upholstery member having an air bag door appliedwith three-dimensional decorations such as embossing. It has beenrequired to provide the position corresponding to the air bag door ofsuch a vehicle upholstery member having the air bag door with abreak-scheduled line (which may be also referred to as a tear line or asplit line) as a thin-walled portion for reliably opening the air bagdoor by the deployment force of the air bag. In order not to impairthree-dimensional decorations in a vehicle upholstery member having anair bag door, there has been a demand for an invisible typebreak-scheduled line that is formed on the back side of the vehicleupholstery member having the air bag door and that cannot be recognizedfrom the front surface side.

Thus, when the invisible type break-scheduled line is formed from theback side of a skin, a heat-cutting jig such as a laser cutter, ahigh-frequency cutter, an ultrasonic cutter, or a heated blade has beenemployed. JP 2000-95056 A has disclosed the use of a heated comb-shapedcutting blade as shown in FIG. 21 because the above-mentionedheat-cutting jigs render a vehicle upholstery member having an air bagdoor susceptible to damage from heat.

JP 06-218811 A has disclosed a method in which, when a groove is formedin a sheet skin made of a thermoplastic plastic, a pressing member 241having a shape corresponding to that of the groove is ultrasonicallypressed against and fused to the sheet skin 211 by a given force, asshown in FIG. 18.

Moreover, a method of producing a vehicle upholstery member having aninvisible type air bag door has been disclosed in JP 2000-351335 A,which includes a holding base for processing a thin wall 265 capable ofplacing an air bag lid-equipped skin 262 turned over therein, and acutting tool 270 capable of cutting the skin along a guide groove forprocessing a split line 266 formed in a guide body 267 arranged over theskin that is placed in the holder for processing a thin wall 265, asshown in FIG. 19.

Furthermore, in a production method disclosed in JP 2000-159047 A, whena skin for a vehicle interior-sided member having an air bag door ismolded in a vacuum, a sheet for a skin 221 is thermally softened andaspirated into a vacuum mold 223, thereby being shaped, and then acutting blade 227 is pressed against the position of a split-scheduledportion 222 to be formed in a skin 221 relative to the air bag door ofthe sheet for a skin while keeping the sheet for a skin aspirated in thevacuum mold 223, to form the split-scheduled portion 222 having a grooveshape, as shown in FIG. 20 (a)- 20 (b) .

However, in the formation of a break-scheduled line using the heatedcomb-shaped cutting blade described in JP 2000-95056 A, a continuousline could not be formed. Therefore, for example if the thickness or thelike of a vehicle upholstery member having an air bag door was uneven,it was difficult to construct an air bag door positioned below thevehicle upholstery member having the air bag door to reliably open bythe deployment force of an air bag. Moreover, even in the use of theheated comb-shaped cutting blade described in JP 2000-95056 A, etc.,there was a problem that, due to a large heat capacity retained in thecutting edge, not a little heat was affected on its surroundings.Consequently, in the case of a skin having a relative thin thickness,the existence of a break-scheduled line could be recognized from thefront surface side, resulting in a problem of facilitating reduction inthree-dimensional decorative characteristics such as embossing.Furthermore, for measuring the depth of a break-scheduled line with anoptical film thickness measurement device, a heated comb-shaped cuttingblade having a relatively large area had to be used.

Alternatively, in the formation of a groove (break-scheduled line)described in JP 06-218811 A, there was a problem with the accumulationof a fused thermoplastic around the groove, which causes pebbling. Thus,in the case of a skin having a relatively thin thickness, the existenceof a break-scheduled line could be recognized from the front surfaceside, resulting in a problem of facilitating reduction inthree-dimensional decorative characteristics such as embossing. Therewas also a problem with reduction in adhesiveness between the skin and afoam layer as a lower layer due to irregularities occurring in the backsurface. Besides, because a pressing member having a relatively largearea had to be used for measuring the depth of the groove with anoptical film thickness measurement device, it was more difficult toprovide a vehicle upholstery member having an air bag door with highprecision and excellent invisibility (non-visibility).

Alternatively, in the formation of a split line (break-scheduled line)described in JP 2000-351335 A, because the skin was bent with its backsurface convexed with the holding base for processing a thin wall, largeirregularities were formed in the back surface of the skin having thesplit line when the skin was flattened after the formation of the splitline. As a result, it was difficult to form the skin uniformly with afoam layer and the like. Moreover, because the portion where the splitline was formed was rendered open when the skin was flattened afterforming the split line, there was a problem with deterioration in theinvisibility (non-visibility) of the skin from the front surface side.

Further, in the formation of a split-scheduled portion (break-scheduledline) described in JP 2000-159047 A, because the position of thesplit-scheduled portion to be formed in the skin relative to the air bagdoor of the sheet for a skin was created while keeping the sheet for askin aspirated in the vacuum mold, the displacement of the position ofthe sheet for a skin was hardly caused. However, because of thethermally soften sheet for a skin, it was difficult to accuratelycontrol the position of the split-scheduled portion to be formed afterthe sheet for a skin was allowed to reach room temperature. Moreover,when the skin was flattened after forming the split-scheduled portion,large irregularities were formed in the back surface of the skin havingthe split-scheduled portion. As a result, it was difficult to form theskin uniformly with a foam layer and the like, in addition to inferiorinvisibility. Besides, for measuring the depth of the split-scheduledportion described in JP 2000-159047 A with an optical film thicknessmeasurement device, a groove-shaped split-scheduled portion having arelatively large width had to be formed.

Thus, the present invention has been accomplished in light of theseproblems. An object of the present invention is to provide a vehicleupholstery member having an air bag door, in which an air bag-developingportion in a steering wheel, an instrument panel, or the like in avehicle cannot be recognized from the front surface side and the depthof a break-scheduled line can be easily and precisely measured with anoptical film thickness measurement device; a method of producing thesame; and a device for producing the same.

DISCLOSURE OF THE INVENTION

[1] According to the present invention, provided is a vehicle upholsterymember having a air bag door equipped with a fabricated skin, wherein aportion of the back surface of the skin corresponding to the portionwhere the vehicle air bag is installed is formed with a break-scheduledline that is not so deep as to reach the surface of the skin and adaptedto assume a substantially V-shaped groove when the skin is bent with itsback surface convexed.

Owing to such construction, the break-scheduled line formed in the skinis adapted to assume a substantially V-shaped groove only when thevehicle-upholstery member having the air bag door is bent with its backsurface convexed. Therefore, the vehicle upholstery member having theair bag door that has excellent invisibility and can be easily andreliably developed by a given deployment force of the air bag can beprovided. When the skin is bent with its back surface convexed, such abreak-scheduled line is adapted to assume a substantially V-shapedgroove and thus the depth of the break-scheduled line can be easily andprecisely measured with an optical film thickness measurement device,for example, a laser-system or infrared radiation-system film thicknessmeasurement device.

Moreover, for constructing the vehicle upholstery member having the airbag door of the present invention, it is preferred that a surface havingthe break-scheduled line (back surface of the skin) is renderedsubstantially flat when the skin is flattened.

[2] According to an alternative aspect of the present invention, amethod of producing a vehicle upholstery member having a fabricatedskin-equipped air bag door is characterized by comprising the followingsteps (A) to (C) in order:

(A) substantially flatly mounting the skin on a support base;

(B) forming a break-scheduled line having a depth that is not so deep asto reach the surface of the skin with a cutting blade; and

(C) measuring the depth of the break-scheduled line or the thickness ofthe remaining portion with the incision of the break-scheduled lineopened.

By practicing the method as above, the break-scheduled line is formedwhile keeping the vehicle upholstery member substantially flat. It istherefore possible to precisely and quickly form the break-scheduledline, the depth of which or the thickness of the remaining portion iseven as a whole. Thus, the vehicle upholstery member having the air bagdoor that has excellent invisibility and is capable of easily andreliably deploying by a given deployment force of the air bag can beefficiently provided. In addition, the depth of the break-scheduled lineor the thickness of the remaining portion is measured with the incisionof the break-scheduled line opened and can be therefore quickly andprecisely measured with an optical film thickness measurement device,for example, a laser-system or infrared radiation-system film thicknessmeasurement device.

Moreover, for practicing the method of producing the vehicle upholsterymember having the air bag door of the present invention, it is preferredthat, at the step (C), a protrusion arranged in the support base ismoved up to a given height and pressed upward against the skin tothereby open the incision of the break-scheduled line.

[3] According to a further alternative aspect of the present invention,a method of producing a vehicle upholstery member having a fabricatedskin-equipped air bag door is characterized by comprising the followingsteps (a) to (c):

(a) partially or entirely bending the skin with its back surfaceconvexed;

(b) forming a break-scheduled line that is not so deep as to reach thesurface of the vehicle upholstery member having the air bag door with acutting blade; and

(c) measuring the depth of the break-scheduled line or the thickness ofthe remaining portion with the incision of the break-scheduled lineopened.

By practicing the method as above, it is possible to efficiently providethe vehicle upholstery member having the air bag door that has excellentinvisibility and is capable of easily and reliably deploying by a givendeployment force of the air bag. In addition, the depth of thebreak-scheduled line or the thickness of the remaining portion ismeasured with the incision of the break-scheduled line opened and can betherefore quickly and precisely measured with an film thicknessmeasurement device, for example, a laser-system or infraredradiation-system film thickness measurement device.

[4] According to a further alternative aspect of the present invention,provided is a device for producing a vehicle upholstery member havingair bag door equipped with a fabricated skin, which is characterized bycomprising a support base for substantially flatly mounting the skinthereon, a cutting blade for forming a break-scheduled line in the skin,and measuring means for measuring the depth of the break-scheduled lineor the thickness of the remaining portion, wherein the measuring meansis used to measure the depth of the break-scheduled line or thethickness of the remaining portion, with the incision of thebreak-scheduled line opened.

Owing to such construction, the break-scheduled line is formed whilekeeping the vehicle upholstery member substantially flat. Therefore, itis possible to precisely and quickly form the break-scheduled line, thedepth of which or the thickness of the remaining portion is even as awhole. Thus, the vehicle upholstery member having the air bag door thathas excellent invisibility and is capable of easily and reliablydeploying by a given deployment force of the air bag can be efficientlyprovided. Moreover, according to such a production device, the depth ofthe break-scheduled line or the thickness of the remaining portion ismeasured with the incision of the break-scheduled line opened and can betherefore quickly and precisely measured with an optical film thicknessmeasurement device, for example, a laser-system or infraredradiation-system film thickness measurement device.

Besides, for constructing the device for producing the vehicleupholstery member having the air bag door, it is preferably to compriseposition-detecting means for detecting the altitude of the cuttingblade.

In addition, for constructing the device for producing the vehicleupholstery member having the air bag door, it is preferred to comprisestate-detecting means for detecting the state of the cutting blade.

In addition, for constructing the device for producing the vehicleupholstery member having the air bag door, it is preferred that thesupport base is provided with a suction portion for fixing the skintherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) and 1(b) are, respectively, a sectional view of a vehicleupholstery member having an air bag door in a first embodiment.

FIGS. 2( a) to 2(c) are perspective views showing an example of a sheetobject.

FIGS. 3( a) to 3(c) are perspective views showing an example of a sheetobject.

FIG. 4 (b) is a diagram for illustrating the state of a break-scheduledline when a skin is flattened; and FIG. 4( a) is a diagram forillustrating the state of an opened incision of the break-scheluledline.

FIG. 5 (a) is a diagram for illustrating the shape of a break-scheduledline (H-shaped); and FIG. 5( c) is a diagram for illustrating the shapeof a further alternative break-scheduled line (a double-headedarc-shaped).

FIG. 6( a) to 6(c) are, respectively, a diagram for illustrating aprotrusion used for opening the incision of each of the break-scheduledlines in FIGS. 5( a) to 5(c).

FIGS. 7( a) to 7(f) are, respectively, a diagram for illustrating amethod of producing a vehicle upholstery member having an air bag doorin a second embodiment.

FIGS. 8( a) to 8(f) are, respectively, a diagram for illustrating amethod of producing a vehicle upholstery member having an air bag door.of the break-scheduled lines in FIGS. 7( a) to 7(c) (No. 1).

FIGS. 9( a) to 9(f) are, respectively, a diagram for illustrating amethod of producing a vehicle upholstery member having an air bag doorin a third embodiment.

FIGS. 10( a) to 10(d) are, respectively, a diagram for illustrating amethod of producing a vehicle upholstery member having an air bag doorin a third embodiment.

FIG. 11 is a perspective view of a device for producing a vehicleupholstery member having an air bag door in a forth embodiment.

FIG. 12( a) to (c) are, respectively, a diagram for illustrating aprotrusion used for opening the incision of each of the break-scheduledlines in FIGS. 5( a) to 5(c).

FIGS. 13( a) to 13(f) are, respectively, a diagram for illustrating theshape of protrusion.

FIGS. 14( a) to 14(f) are, respectively, a diagram for illustrating amodification example of the shape of a protrusion. having an air bagdoor in a third embodiment (No. 2).

FIG. 15 (a) to 15(b) are, respectively, a diagram for illustrating amethod of detecting the state of a cutting blade.

FIGS. 16( a) to 16(c) are, respectively, a diagram showing a sectionalview of a skin having a break-scheduled line when a film thickness ismeasured with a film thickness measurement device.

FIGS. 17 is a diagram for illustrating a conventional method ofproducing a vehicle upholstery member having an air bag door.

FIGS. 18 is a diagram for illustrating a conventional method ofproducing a vehicle upholstery member having an air bag door.

FIGS. 19 is a diagram for illustrating a conventional method ofproducing a vehicle upholstery member having an air bag door.

FIGS. 20 is a diagram for illustrating an alternative conventionalmethod of producing a vehicle upholstery member having an air bag door.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a device for producing a vehicle upholstery member havingan air bag door of the present invention and a production method by theuse of the device will be described in detail with reference to drawingsas appropriate.

FIRST EMBODIMENT

A first embodiment is, as illustrated in FIGS. 1( a) and 1(b), a vehicleupholstery member having an air bag door 10 equipped with a fabricatedskin 11, which is characterized in that a corresponding portion 12 of aback surface A of the skin 11 to the portion where a vehicle air bag 21is installed is provided with a break-scheduled line 17 that is not sodeep as to reach a surface B of the skin 11 and adapted to assume asubstantially V-shaped groove when the skin 11 is bent with its backsurface convexed.

Incidentally, in the description below, a surface sheet other than asubstrate and a foam layer that have the function of accommodating anair bag in the vehicle upholstery member having the air bag doorillustrated in FIG. 1 may be also simply referred to as a skin; orotherwise, the whole vehicle upholstery member having the air bag doorillustrated in FIG. 1 may be also simply referred to as a skin.

1. Vehicle Upholstery Member having Air Bag Door

(1) Kind

Preferably, the fabricated skin in the vehicle upholstery member havingthe air bag door is exemplified by, but not particularly limited to, athree-dimensional material shaped along the outside shape of afabricated sheet object or a molded product such as an automobilecomponent. Moreover, the fabricated skin is preferred to be decorated,for example, with surface convexo-concave such as embossing or embosseddesigns on the surface or by the printing of patterns, characters,symbols, or the like, or is preferred to be improved in smoothness bysurface polishing.

Furthermore, the fabricated skin is preferably made of a thermoplasticresin or a thermosetting resin, the kind of which is not particularlylimited. However, taking into consideration actual environments wherethe vehicle upholstery member having the air bag door is utilized, it ismore preferable to use a thermoplastic elastomer such as a thermoplasticurethane elastomer, a thermoplastic styrene elastomer, a thermoplasticnaphthalene elastomer, or thermoplastic olefin elastomer, which canmaintain excellent mechanical strength even at relatively hightemperatures not lower than 70° C. and can maintain good flexibility andsmooth textures even at low temperatures not higher than 0° C.

Concerning the kind of the thermoplastic resin or the thermosettingresin, a resin that maybe molded by means of powder slush molding, forexample, the aboved mentioned thermoplastic elastomer, a B-stage epoxyresin, or even a vinyl chloride resin is also preferably used.

This is because, for constructing the fabricated skin, a large skinhaving a complex shape applied to a vehicle can be easily and preciselyformed if powder slush molding is available.

It is noted that a powder resin in which an inorganic substance such aszeolite or calcium carbonate ranging, for example, from 0.1 to 30 wt. %relative to the whole quantity is added to a used resin is preferablyutilize when powder slush molding is carried out. This is because theaddition of an inorganic substance in a given amount improves thedispersibility of a powder resin and significantly improves thedecorative characteristics of the fabricated skin.

(2) Configuration

The configuration of the skin in the vehicle upholstery member havingthe air bag door may be, for example, but not particularly limited to,any of skins used in vehicle components such as an in-front panel asshown in FIG. 2( a), a door as shown in FIG. 2( b), a chair as shown inFIG. 2( c), a console box as shown in FIG. 3( a), and a bumper as shownin FIG. 3( b).

Alternatively, as an modification example of the vehicle upholsterymember having the air bag door, a complexed structure composed of theabove-mentioned skin in combination with a metal component, a ceramiccomponent, a glass component, a paper component, a wood component, orthe like is also preferred.

(3) Thickness

The thickness of the skin for the vehicle upholstery member having theair bag door is preferably exemplified by, but not particularly limitedto, a value within the range of 0.5 to 5 mm.

This is because, if such a skin has a thickness less than 0.5 mm, theremay be difficulty in forming a break-scheduled line or may be reductionin invisibility; whereas if the skin has a thickness greater than 5 mm,there may be difficulty in reliably opening an air bag door when thedeployment force of an air bag occurs.

Thus, the skin for the vehicle upholstery member having the air bag doormore preferably has a thickness within the range of 0.7 to 3 mm, evenmore preferably 0.9 to 2mm.

(4) Layered Body

Preferably, the vehicle upholstery member having the air bag door isconstructed as a layered body comprising, on a back side A of the skin11, a foam layer and a substrate 15 accommodating the air bag 21 andprovided with a thin-walled portion 19 along an air bag door 18 thatopens when the deployment force of the air bag 21 occurs, as shown inFIGS. 1( a) and 1(b).

This is not only because the foam layer on the back side of the skinprovides for excellent three-dimensional decorative characteristics orsmooth textures, but because the relatively soft foam layer throughwhich the skin is easily disrupted enables the air bag door to reliablyopen when the deployment force of the air bag occurs. Moreover, theinclusion of a certain substrate accommodating the air bag and providedwith the thin-walled portion along the air bag door improves thecapability to accommodate the air bag and allows the air bag door tofurther reliably open when the deployment force of the air bag occurs.

2. Break-Scheduled Line

(1) Arrangement and Configuration

The arrangement (formation position) of the break-scheduled line ischaracterized in that the break scheduled line is provided in the backsurface A of the skin 11, as shown in FIGS. 1( a) and 1(b). Namely, thegiven invisibility of the vehicle upholstery member having the air bagdoor 10 is secured by the absence of the break-scheduled line 17 in thesurface of the skin 11.

Moreover, the conformation of the break-scheduled line is characterizedin that the break-scheduled line is adapted to assume a substantiallyV-shaped groove when the skin 11 is bent with its back surface Aconvexed, as shown in FIG. 4( a).

That is, because the break-scheduled line can assume a V-shaped grooveeven for a short time, the depth of the break-scheduled line is easilyand precisely measured with an optical film thickness measurementdevice.

Additionally, as for the conformation of the break-scheduled line, whenthe skin 11 is flattened as shown in FIG. 4( b), it is preferred thatthe back surface A of the skin 11 having the break-scheduled line 17 isrendered substantially flat.

This is because the back surface of the skin is substantially flatwithout irregularities resulting from the break-scheduled line withinnormal use, so that a layering process can be carried out with ease andthe excellent adhesiveness of the back surface of the skin to the foamlayer and the substrate can be attained when the foam layer and thesubstrate is layered thereon.

A measure of the back surface flatness of the skin is that noirregularity exists, which can be perceived by, for example, anexamination by the touch.

(2) Shape

The shape (pattern) of the break-scheduled line is preferred to beconstructed of one or more straight line(s) and a straight line or acurve vertically or diagonally intersecting the one or more straightline(s).

This is because such construction not only facilitates the formation ofthe break-scheduled line, but allows the air bag door to reliably openalong the break-scheduled line when the deployment force of the air bagoccurs.

More particularly, it is preferred that a straight line and a curvedline are combined to give a double-headed arrow-shaped line as shown inFIG. 5( a), a H-shaped line as a whole as shown in FIG. 5 (b), or adouble-headed arc-shaped line as shown in FIG. 5( c).

This is because, in the double-headed arrow-shaped line as shown in FIG.5( a), only one or more straight line(s) and an oblique line areutilized to allow for the formation of the break-scheduled line withgood reproducibility and ease, and to allow the air bag door to morereliably open along the break-scheduled line when the deployment forceof the air bag occurs. Alternatively, in the H-shaped line as shown inFIG. 5( b), only one horizontal straight line and a straight linevertically intersecting the horizontal straight line are used to allowfor the formation of the break-scheduled line with good reproducibilityand ease, and to allow the air bag door to reliably open along thebreak-scheduled line. Moreover, in the case of the double-headedarc-shaped line as shown in FIG. 5( c), the air bag door can be morereliably opened along the break-scheduled line constructed of onehorizontal straight line and two semi-arc curves.

It is noted that, for making the break-scheduled line into as any ofshapes (patterns) as shown in FIGS. 5( a) to 5(c), each of patternedprotrusions as shown in FIGS. 6( a) to 6(c) is preferably used.

(3) Depth

The depth of the break-scheduled line is preferred to be defined inlight of the open/close capability of the air bag door, the balance ofinvisibility, or mechanical strength, and the like, and is preferablyexemplified by a value in the range of 0.1 to 1 mm.

This is because, if such a break-scheduled line has a depth less than0.1 mm, the air bag door may be significantly reduced in the open/closecapability; whereas the break-scheduled line having a depth greater than1 mm may reduce invisibility or may significantly depress the mechanicalstrength of the skin.

Thus, the break-scheduled line more preferably has a depth in the rangeof 0.2 to 0.8 mm, even more preferably 0.3 to 0.7 mm.

The depth of the break-scheduled line is also preferred to be defined inlight of the thickness of the skin. That is, when the skin takes t1 (mm)in thickness and the break-scheduled line takes t2 (mm) in depth, it ispreferred to meet the relationship of t1×0.3<t2<t1×0.7.

This is because, if the depth of the break-scheduled line t2 smallerthan t1×0.3, the air bag door may be significantly reduced in theopen/close capability; whereas the depth of the break-scheduled line t2greater than t1×0.7 may reduce invisibility or may significantly depressthe mechanical strength of the skin.

Thus, for the depth of the break-scheduled line, it is more preferred tomeet the relationship of t1×0.4<t2<t1×0.6.

(4) Width

It is preferred that the width of the break-scheduled line takes a valueallowing the break-scheduled line to assume a substantially V-shapedgroove when the skin 11 is bent with its back surface A convexed asshown in FIG. 6( a), and takes a value rendering the back surface A ofthe skin 11 having the break-scheduled line 17 substantially flat whenthe skin 11 is flattened as shown in FIG. 4( b).

Thus, the break-scheduled line preferably has a width within the rangeof 0.005 to 0.2 mm, more preferably 0.01 to 0.1 mm, even more preferably0.02 to 0.08 mm.

SECOND EMBODIMENT

A second embodiment is, as shown in FIGS. 7( a) to 7(f), a method ofproducing a vehicle upholstery member having an air bag door equippedwith a fabricated skin 11, which is characterized by comprising thefollowing steps (A) to (C) in order:

(A) substantially flatly mounting the skin 11 on (lion in a pamphlet) asupport base 31;

(B) forming a break-scheduled line 17 that is not so deep as to reachthe surface of the skin 11 with a cutting blade 35; and

(C) measuring the depth of the break-scheduled line or the thickness ofthe remaining portion with the incision of the break-scheduled line 17opened.

Incidentally, a device for producing a vehicle upholster member havingan air bag door used in the second embodiment is same as that explainedin a forth embodiment that will be described below, so that thedescription is omitted here.

1. Preliminary Step

Prior to practicing the step (A) according to the second embodiment, itis preferred to prepare the skin for the vehicle upholstery memberhaving the air bag door. That is, this skin is same as that explained inthe first embodiment, so that the description is omitted here.

2. Step (A)

At the step (A) according to the second embodiment, the fabricated skin11 is substantially flatly mounted on the support base 31, as shown inFIGS. 7( a) and 7(b).

For example, it is preferred that, after the support base 31substantially flattened and equipped with a protrusion 33 having a givenheight that moves up and down is prepared as shown in FIG. 7( a), theskin 11 is mounted on the support base 31 equipped with the protrusion33, with its surface B turned downward (i.e., a back surface A of theskin 11 is turned upward) as shown in FIG. 7( b).

After mounted, the skin is preferred to be aspirated from its frontsurface side through a suction hole using a vacuum pump or the like.This is because, by aspirating the skin as above, the skin can betemporarily fixed in a desired position even though the skin has acomplex shape or is large. Moreover, such aspiration of the skin caneffectively prevent reduction in the precise formation of thebreak-scheduled line, which attributes to the displacement of the skinwhen the break-scheduled line is formed. Furthermore, unlike amechanical fixation method, it is possible to move the skin immediatelyafter the aspiration of the skin is terminated.

In a method of fixing the skin 11, as shown in FIG. 8, (a) to (f) it ispreferred to use a cover material 65 on the back surface side of theskin.

This is because such practice prevents the possibility that the locationother than a predetermined location is cut when the break-scheduled lineis formed in the skin. As a result, the step of forming thebreak-scheduled line in the skin can be precisely and quickly carriedout.

It is noted that the cover material is preferably formed out of a metalor the like and provided with an opening in a given place.

3. Step (B)

At the step (B) according to the second embodiment, as shown in FIG. 7(c), the break-scheduled line 17 that is not so deep as to reach thesurface is formed in the back surface A of the skin 11 with the cuttingblade 35. Preferably, the cutting blade used here is, for example, acutter or a razor in view of the excellent invisibility of the vehicleupholstery member having the air bag and low costs.

However, according to the production method of the present invention,the skin is cut with it deformed and therefore relatively precisely andflatly formed even using a heat-cutting jig. Thus, it is also preferredthat a heat-cutting jig such as a laser cutter, a high-frequency cutter,an ultrasonic cutter, or a heated blade is used alone or in combinationwith a non-heat-cutting jig.

Moreover, either before or after, or both before and after practicingthe step (B), it is preferred to examine the state of the cutting blade.

This is because, by examining the state of the cutting blade before theformation of the break-scheduled line, the depth of the break-scheduledline formed in the skin or the thickness of the remaining portion can bemore accurately controlled. Alternatively, by examining the state of thecutting blade after the formation of the break-scheduled line, theoperation of the device can be stopped to replace the blade if anydamage is found on the cutting edge.

In addition, at the step (B), it is preferred to conduct the temperaturecontrol of the cutting blade when the break-scheduled line is formedusing the cutting blade. That is, the temperature of the cutting bladein use sometimes excessively rises, and as a result, it may be difficultto precisely and quickly form the break-scheduled line.

Thus, the temperature of the cutting blade preferably takes a valuewithin the range of 0 to 50° C., more preferably 10 to 40° C., even morepreferably 20 to 35° C.

It is noted that the direct monitoring of the temperature of the cuttingblade using a heat conductor or the like is preferred and themeasurement of the temperature using an infrared thermometer kept fromcontact with the cutting blade is also preferred.

4. Step (C)

At the step (C) according to the second embodiment, as shown in FIGS. 7(e) and 7(f), the skin 11 is deformed to let the break-scheduled line 17in the back surface A of the skin 11 be a substantial vertex and thedepth of the break-scheduled line 17 or the thickness of the remainingportion is measured while keeping the incision of the break-scheduledline 17 opened.

For example, at the step, as shown in FIG. 7( e), the protrusion 33moving up and down is pressed against the portion of the formedbreak-scheduled line 17 from the front surface B side of the skin 11(back surface side of the break-scheduled line) on the support base 31to open the incision of the break-scheduled line 17 formed in the skin11, and, as shown in FIG. 7( f), the depth of the break-scheduled line17 or the thickness of the remaining portion is measured with a filmthickness measurement device 39.

This is because, by measuring the depth of the break-scheduled line orthe like with the incision of the break-scheduled line opened, the depthof the break-scheduled line or the thickness of the remaining portioncan be easily and reliably measured even in the case that the width ofthe break-scheduled line is narrowed or the depth thereof is shortenedfor improving the invisibility of the vehicle upholstery member.

A method of measuring the depth of the break-scheduled line or thethickness of the remaining portion is preferably carried out in at least2 or more places, more preferably in 3 or more places. This is because,by measuring the film thickness in several places as above, a mean valuecan be determined even though the fabricated skin has a somewhat uneventhickness. Thus, the break-scheduled line having an even film thicknessas a whole can be formed and therefore the air bag door is allowed toreliably open along the break-scheduled line when the deployment forceof the air bag occurs.

It is noted that, preferably, the thickness of the fabricated skin isalso measured at the step before forming the break-scheduled line in theskin. This is because, by measuring the film thickness before and afterforming the break-scheduled line as above, the break-scheduled linehaving a more even film thickness as a whole can be formed and the airbag door is allowed to more reliably open along the break-scheduled linewhen the deployment force of the air bag occurs.

THIRD EMBODIMENT

A third embodiment is, as illustrated in FIGS. 9( a) to 9(f), a methodof producing a vehicle upholstery member 10 having an air bag door 10equipped with a fabricated skin 11, which is characterized by comprisingthe following steps (a) to (c):

(a) partially or entirely bending the skin 11 with its back surface Aconvexed;

(b) forming a break-scheduled line 17 that is not so deep as to reachthe surface with a cutting blade 35; and

(c) measuring the depth of the break-scheduled line 17 or the thicknessof the remaining portion with the incision of the break-scheduled line17 opened.

The production method in the third embodiment can be carried out in asubstantially same manner as the second embodiment except that thebreak-scheduled line is formed while the skin is bent with its backsurface convexed, so that the method will be described here with aparticular emphasis on the step (a).

1. Preliminary Step

Prior to practicing the step (a), it is preferred to prepare the skinfor the vehicle upholster member having the air bag door as in thesecond embodiment.

2. Step (a)

At the step (a) according to the third embodiment, the skin is deformedto let the place of the break-scheduled line to be formed in the backsurface of the skin be a substantial vertex and the skin is partially orentirely bent into a convex shape.

That is, such practice allows for easy formation of the break-scheduledline that adapted to assume a V-shaped groove when the skin is bent intoa convex shape and allows for easy and precise measurement of the depthof the break-scheduled line with an optical thickness measurementdevice.

(1) Bending procedure 1

Here, bending procedures at the step (a) are not particularly limited.For example, it is preferred that after a support base 31 equipped witha protrusion 33 moving up and down is prepared as shown in FIG. 9( a),the skin 11 is mounted on the support base with its surface B turneddownward (i.e., the back surface A of the skin 11 is turned upward) asshown in FIG. 9( b).

Next, as shown in FIG. 9( c), it is preferred that the protrusion 33moving up and down is pressed against a formation place 27 of thebreak-scheduled line 17 from the surface B side of the skin 11 on thesupport base 31 (back surface side of the break-scheduled line) to bendonly a given place of the skin 11.

This is because such practice enables the skin in an arbitrary place tobe bent to some extent by the protrusion moving up and down, regardlessof the thickness or the material of the skin, and allows for easy andprecise formation of several break-scheduled lines varied in aspects.

(2) Bending Procedure 2

Alternatively, in bending procedures at the step (a), it is alsopreferred to use a support base 31 equipped with a fixed protrusion 33having a given height as shown in FIG. 10( a). That is, following thepreparation of the support base 31, preferably, the skin 11 is mountedon the support base 31 equipped with the protrusion 33 having a givenheight with its surface B turned downward, more particularly, with itsback surface A turned upward, and a given place of the skin 11 isprecisely bent to some extent, as shown in FIG. 10 (b).

This is because, even though the break-scheduled line is formed in largeskin, such practice allows the skin to be quickly bent to some extentand allows for easy and precise formation of the break-scheduled line.Moreover, by altering the height of the protrusion, severalbreak-scheduled lines varied in aspects can be easily formed even usinga simple production device.

(3) Bending Procedure 3

For practicing the step (a), it is preferred that after mounted, theskin is aspirated from its front surface side through a suction holeusing a vacuum pump or the like, or otherwise fixed on a cover materialused on the back surface side of the skin, as described in the secondembodiment.

3. Steps (b) and (c)

After the step (a) is practiced, preferably, the break-scheduled line isformed, followed by measuring the depth of the break-scheduled line orthe thickness of the remaining portion with the incision of thebreak-scheduled line opened in a V shape, in conformance with the secondembodiment.

FORTH EMBODIMENT

A forth embodiment is, as illustrated in FIG. 11, a device 30 forproducing a vehicle upholstery member having air bag door equipped witha fabricated skin, which is characterized by comprising a support base31 for substantially flatly mounting a skin thereon, a cutting blade 35for forming a break-scheduled line in the skin, and measuring means 39for measuring the depth of the break-scheduled line or the thickness ofthe remaining portion, wherein the measuring means 39 is used to measurethe depth of the break-scheduled line or the thickness of the remainingportion, with the incision of the break-scheduled line opened.

Incidentally, the vehicle upholstery member having the air bag door andthe break-scheduled line in the forth embodiment is same as thosedescribed in Example 1, so that the description is omitted here.

1. Support Base

(1) Basic Structure

The basic structure of the support base is not particularly limited aslong as the support base is constructed to substantially flatly mountthe skin of the vehicle upholstery member having the air bag doorthereon. For example, it is preferred that the support base isconstructed to have the upper surface that is substantially flattenedand held in the horizontal direction, as shown in FIG. 11 and FIG. 7(a). In addition, the support base 31 is preferred to have an opening 55that corresponds to the shape of a protrusion 33 described below andthat allows for up-and-down movements of the protrusion 33.

(2) Protrusion

I. Structure

It is preferred that the support base 31 is equipped with the protrusion33 as shown in FIG. 11, FIG. 7( e), or the like.

This is because the protrusion is pressed upward against the skin on thesupport base, that is, from the back surface side of the break-scheduledline (surface side of the skin), and the incision of the break-scheduledline is reliably opened to thereby allow for easy and precisemeasurement of the depth of the break-scheduled line or the thickness ofthe remaining portion.

Moreover, as shown in FIGS. 6( a) to 6(c), it is preferred that such aprotrusion is constructed of one structure as a whole in terms of simpledesign and production. However, as shown in FIGS. 12( a) to 12(c), adividable protrusion 33 a as a whole composed of several independentcomponents (linear or curved) corresponding to the shape of theprotrusion is also preferred. This is because such a dividableprotrusion allows for up-and-down movements of a portion of theprotrusion to selectively open only the portion where the depth of thebreak-scheduled line or the thickness of the remaining portion ismeasured. Thus, in response to the shape or the size of thebreak-scheduled line, the depth or the like can be more preciselymeasured.

II. Whole Shape 1

The pattern shape of the protrusion is preferably constructed of one ormore linear object(s) and a linear object or a curved object verticallyand horizontally intersecting the one or more linear object(s). Moreparticularly, it is preferred that the protrusion has a shapecorresponding to the shape (pattern) of the break-scheduled line formedin the skin. For example, if the break-scheduled line formed in the skinhas a shape (pattern) as shown in FIGS. 5( a) to 5(c), the pattern shapeof the protrusion in the support base is preferred to be patterned asshown in FIGS. 6( a) to 6(c).

This is because such construction enables the incision of thebreak-scheduled line to be reliably opened even in the case that thebreak-scheduled line formed in the skin has a complex shape.

III. Shape 2

The vertical sectional shape of the protrusion is not particularlylimited. Preferably, the protrusion is any of those capable of openingthe incision of the break-scheduled line when pressed against thebreak-scheduled line formed in the skin from the back surface side. Forexample, it is preferred that the vertical section has a shape such as arectangle, a trapezoid, a cylindrical section having a curved end, asquare, an acicular section, or a semicircle as shown in FIGS. 13( a) to13(f), respectively. It is also preferred that the entire or partialupper surface of the protrusion 33 is provided with a flat portion 38 ora convex portion 37 as shown in FIGS. 14( a) to 14(f).

IV. Given Height

A given height of the protrusion moved upward is not particularlylimited, and is preferably exemplified by a value within the range of0.1 to 10 mm from the surface of the support base. This is because, ifsuch a protrusion has a given height less than 0.01 mm, the incision ofthe break-scheduled line in the skin cannot be sufficiently opened,resulting in reduction in measurement capability of an optical device;whereas the protrusion having a given height greater than 10 mm mayreduce invisibility and may significantly depress the mechanicalstrength of the skin.

Thus, the protrusion preferably has a given height within the range of0.2 to 7 mm, more preferably 0.3 to 5 mm, from the surface of thesupport base.

V. Operation

For operating the protrusion, it is preferred that the protrusion ispartially or entirely moved upward and downward before or after theformation of the break-scheduled line 17. For example, regarding theconstruction of the protrusion, it is preferred that the skin 11 isflatly mounted on the support base 31 and, for example, after aspiratingand fixing the skin 11, the break-scheduled line 17 is formed in theflattened skin 11, followed by moving upward the protrusion 33 moving upand down via the opening 55 provided in the support base 31 to allow theincision of the break-scheduled line 17 formed in the skin 11 to open,as illustrated in FIG. 7( a) to (e).

This is because, when the break-scheduled line 17 is formed, theprotrusion 33 is located in the position lower than the surface of thesupport base 31 and thus the flatness of the surface of the skin 11allows for quick and reliable formation of the break-scheduled line. Onthe other hand, after the break-scheduled line 17 is formed, theprotrusion 33 can move up to a given position higher than the surface ofthe support base 31 to sufficiently open the incision of thebreak-scheduled line in the skin.

It is noted that, because the protrusion partially or entirely moves upand down, the incision of the break-scheduled line in the portion to bemeasured can be opened as desired, even though the break-scheduled lineis composed of one or more linear object(s) and the like.

(3) Suction Portion

As shown in FIG. 15, it is preferred that the support base 31 has, as asuction portion, a suction hole 23 composed of several small holesconnected to a suction device (not shown) such as a vacuum pump.

This is because, owing to such construction, the skin can be aspiratedand temporarily fixed in a desired position even though the skin has acomplex shape or is large. Thus, the displacement of the skin when thebreak-scheduled line is formed can be effectively prevented and thebreak-scheduled line can be precisely formed. Moreover, unlike amechanical fixation method, it is possible to move the skin immediatelyafter the aspiration of the skin is terminated.

2. Cutting Blade

The kind of the cutting blade is not particularly limited.

However, more preferred is the use of a cutter or a razor allowing forlow costs, in addition to the acquisition of the vehicle upholsterymember having the air bag door that has excellent invisibility and thesubstantially flat surface (the back surface of the skin) having thebreak-scheduled line when the skin is flattened.

3. Measuring Means

In the measuring means for measuring the depth of the break-scheduledline 17 or the thickness of the remaining portion with the incision ofthe break-scheduled line 17 formed with the cutting blade opened, theremaining portion of the break-scheduled line can be adjusted to have athickness within a given range, based on the measurement value.

Here, the aspect of such measuring means is not particularly limited,and can utilize, for example, an optical or ultrasonic film thicknessmeasurement device. However, it is preferred to use the optical filmthickness measurement device in light of more reliable measurement andsavings in space.

4. Position-Detecting Means

It is also preferred that the production device comprisesposition-detecting means for detecting the altitude of the cuttingblade.

This is because such position-detecting means can detect the altitude ofthe cutting blade as appropriate to adjust the distance between thecutting blade and the skin to a given value at any time. Thus, becauseof the inclusion of the position-detecting means, the break-scheduledline, the depth of which or the thickness of the remaining portion iseven as a whole can be precisely and quickly formed even though thethickness of the skin or the like is altered.

It is noted that the altitude of the cutting blade before or during theformation of the break-scheduled line can be adjusted by detection usingthe position-detecting means 32, for example, laser-styleposition-detecting means 32 provided at a given distance (h2) from anedge 35 a of the cutting blade 35 in the height direction, as shown inFIG. 15( a). That is, by continuously measuring the distance between theposition-detecting means 32 and the surface of the support base 31 tokeep the distance (h1) constant, the altitude of the cutting blade 35can be indirectly adjusted.

Thus, by moving a holding portion 36 of the cutting blade connected tothe position-detecting means 32 the edge 35 a of the cutting blade 35 tokeep the edge 35 a of the cutting blade 35 at a given distance (h3) awayfrom the surface of the support base 31, the break-scheduled line, thedepth of which or the thickness of the remaining portion is even as awhole can be precisely and quickly formed, regardless of the thicknessof the skin 11 or the less.

5. State-Detecting Means

Moreover, it is preferred that the production device comprisesstate-detecting means for detecting the state of the cutting blade. Moreparticularly, the device is preferred to be constructed to allow for theconfirmation that the edge of the cutting blade is in a good state,before forming the break-scheduled line.

This is because, by the inclusion of the state-detecting means, the wayof cutting with the cutting blade can be kept in a constant state, andthe break-scheduled line, the depth of which or the thickness of theremaining portion is even as a whole can be precisely and quicklyformed, even though the kind, the thickness, or the like of the skin isaltered.

In addition, if the state of the edge of the cutting blade is examinedand the damage caused by wear and so on is detected, the operation ofthe device can be stopped to replace the cutting blade. Thus, thevehicle upholstery member having the break-scheduled line, the depth ofwhich or the thickness of the remaining portion is kept even can beobtained.

Here, for the state of the edge of the cutting blade, the deferencebetween the position (h3) of the edge 35 a′ in such a state that theholding portion 36 is returned to the position h1 equal to the positionbefore forming the break-scheduled line as shown in FIG. 15( b) and theoriginal position (h2) of the edge, and the difference in shapes ofshadows are measured using a laser measurement device, an infraredmeasurement device, or the like, to thereby allow for the detection ofthe degree of damage by wear and so on.

EXAMPLES Example 1

A skin with a given shape (300 mm long×450 mm wide×1.0 mm thick) made ofa thermoplastic urethane elastomer (TPU), which was treated with0.1-millimeter-deep embossing was molded. Next, a support base (steelplate) equipped with a protrusion (trapezoid-shaped) protrudable fromthe surface of the support base by up-and-down movements as shown inFIG. 13( b) and having several suction holes was prepared. The skin wasmounted on the support base and kept in the state of aspiration with avacuum device.

Subsequently, after confirming that the surface of the skin is keptflat, a break-scheduled line (scheduled depth: 0.5 mm, scheduled width:0.01 mm) as a thin-walled portion that is not so deep as to reach thesurface of the skin was formed with a cutter as a cutting blade (surfacetemperature: 25° C.).

Subsequently, the protrusion was pressed against the skin from its frontsurface side (back surface side of the break-scheduled line) and LaserDisplacement Meter LC (KEYENCE) was used as a laser-style film thicknessmeasurement device to measure the film thickness of the remainingportion of the break-scheduled line with the incision of thebreak-scheduled line opened. FIG. 16( a) shows a sectional view of theskin having the break-scheduled line obtained by the measurement inExample 1. It is seen from the drawing that the incision of thebreak-scheduled line is opened in a V shape.

Then, as shown in FIG. 1( b), a 2-millimeter-thick foam layer made of anurethane resin and a polypropylene substrate accommodating an air bagwere layered on the back surface side of the skin to give a vehicleupholstery member having an air bag door of Example 1, for carrying outevaluation described below.

(1) Degree of Opening

The protrusion was protruded 0.5 mm from the surface of the support baseand pressed upward against the skin having the formed break-scheduledline to open the incision of the break-scheduled line. Thereafter, itssectional shape was observed with a microscope to evaluate the degree ofopening in the incision (section) of the break-scheduled line accordingto the following criteria:

-   Very good: the incision is a bilaterally equal V-shaped groove and    is opened sufficiently wide;-   Good: the incision is an approximately bilaterally equal V-shaped    groove and is opened relatively wide;-   Fair: the incision is a substantially bilaterally equal V-shaped    groove and, however, its opening is relatively narrow; and-   Bad: the incision has no definite form and is hardly opened.    (2) Invisibility

A 100 W white lamp as a light source was arranged in the back surface ofthe skin having the formed break-scheduled line. Subsequently, while thelight source stays on, the skin was visually observed from its frontsurface side to evaluate the invisibility (non-visibility) of thebreak-scheduled line according to the following criteria:

-   Very good: the break-scheduled line is not recognized at all from    the front surface side;-   Good: the break-scheduled line is hardly recognized from the front    surface side;-   Fair: the break-scheduled line is partially recognized from the    front surface side; and-   Bad: the break-scheduled line is markedly recognized from the front    surface side.    (3) Capability to Measure Film Thickness

The protrusion was protruded 0.5 mm from the surface of the support baseand pressed upward against the skin having the formed break-scheduledline to open the incision of the break-scheduled line. Thereafter, thelaser-style film thickness measurement device described above was usedto measure the thickness of the remaining portion of the break-scheduledline in ten places.

-   Very good: the measurement values vary 5% or less;-   Good: the measurement values vary 10% or less;-   Fair: the measurement values vary 20% or less; and-   Bad: the measurement values vary greater than 20%.    (4) Capability of Development by Air Bag

During developing the accommodated air bag, visual observations was madeto evaluate the capability to develop the vehicle upholstery member bythe air bag according to the following criteria:

-   Very good: entirely developed along the break-scheduled line;-   Good: almost entirely developed along the break-scheduled line;-   Fair: partially developed along the break-scheduled line; and-   Bad: not developed along with the break-scheduled line.

Example 2

In Example 2, a break-scheduled line (scheduled depth: 0.5 mm, scheduledwidth: 0.01 mm) was formed in a skin, followed by layering a foam layerand a polypropylene substrate accommodating an air bag on the backsurface side of the skin to give a vehicle upholstery member having anair bag door of Example 2, as in Example 1, except that the protrusionwas protruded 1 mm from the surface of a support base. Subsequently, thesame evaluations as those of Example 1 were practiced on the skin formedwith the break-scheduled line and the vehicle upholstery member havingthe air bag door.

Example 3

In Example 3, a break-scheduled line (scheduled depth: 0.5 mm, scheduledwidth: 0.01 mm) was formed in a skin, followed by layering a foam layerand a polypropylene substrate accommodating an air bag on the backsurface side of the skin to give a vehicle upholstery member having anair bag door of Example 3, as in Example 1, except that the protrusionwas protruded 2 mm from the surface of a support base. Subsequently, thesame evaluations as those of Example 1 were practiced on the skin formedwith the break-scheduled line and the vehicle upholstery member havingthe air bag door.

Example 4

In Example 4, except that, that a protrusion was protruded 0.5 mm fromthe surface of a support base to bend the back surface of a skin into aconvex shape for forming a break-scheduled line in a skin, and abreak-scheduled line (scheduled depth: 0.5 mm, scheduled width: 0.01 mm)was formed in the convexed skin as shown in FIG. 10( c), a foam layerand a polypropylene substrate accommodating an air bag were layered onthe back surface side of the skin to give a vehicle upholstery memberhaving an air bag door of Example 4, as in Example 1. Subsequently, thesame evaluations as those of Example 1 were practiced on the skin formedwith the break-scheduled line and the vehicle upholstery member havingthe air bag door.

Comparative Example 1

In Comparative Example 1, the same evaluations as those in Example 1 waspracticed, except that a film thickness was measured without pressing aprotrusion upward against the skin, after a break-scheduled line(scheduled depth: 0.5 mm, scheduled width: 0.01 mm) was formed in a skinas in Example 1. That is as shown in FIGS. 7( a) to 7(d), after formingthe break-scheduled line in the skin, a foam layer and a polypropylenesubstrate accommodating an air bag were layered on the back surface sideof the skin to give a vehicle upholstery member having an air bag doorof Comparative Example 1. Subsequently, the same evaluations as those ofExample 1 were practiced on the skin formed with the break-scheduledline and the vehicle upholstery member having the air bag door, withoutpressing the protrusion upward against the skin (i.e., with the skinflat).

FIG. 16( b) shows a sectional view of the skin having thebreak-scheduled line obtained by the measurement of the film thickness.It is seen from the drawing that the incision of the break-scheduledline is not opened, thereby making it difficult to measure the thicknessof the remaining portion of the break-scheduled line.

Comparative Example 2

In Comparative Example 2, a break-scheduled line (scheduled depth: 0.5mm, scheduled width: 0.01 mm) was formed in a skin, followed by layeringa foam layer and a polypropylene substrate accommodating an air bag onthe back surface side of the skin to give a vehicle upholstery memberhaving an air bag door of Comparative Example 2, as in Example 1, exceptthat a heated blade that had been heated to 150° C. was used instead ofthe cutting blade (cutter) in Example 1 and a film thickness wasmeasured while the skin was kept flat without pressing a protrusionagainst the skin. Subsequently, the same evaluations as those of Example1 were practiced on the skin formed with the break-scheduled line andthe vehicle upholstery member having the air bag door.

FIG. 16( c) shows a sectional view of the skin having thebreak-scheduled line obtained by the measurement of the film thickness.It is seen from the drawing that, because the heated blade is used, theskin is molten to generate irregularities around the break-scheduledline.

Comparative Example 3

In Comparative Example 3, a break-scheduled line (scheduled depth: 0.5mm, scheduled width: 0.01 mm) was formed in a skin, followed by layeringa foam layer and a polypropylene substrate accommodating an air bag onthe back surface side of the skin to give a vehicle upholstery memberhaving an air bag door of Comparative Example 3, as in Example 1, exceptthat a ultrasonic vibrating blade was used instead of the cutting blade(cutter) in Example 1 and a film thickness was measured while the skinwas kept flat without pressing a protrusion against the skin.Subsequently, the same evaluations as those of Example 1 were practicedon the skin formed with the break-scheduled line and the vehicleupholstery member having the air bag door.

TABLE 1 Examples Comparative Examples 1 2 3 4 1 2 3 Height of 0.5 1 20.5 0 0 0 protrusion (mm) State of skin Flat Flat Flat Convex Flat FlatFlat bent Cutting jig Cutter Cutter Cutter Cutter Cutter HeatedUltrasonic blade cutter Measured 0.5 0.5 0.5 0.5 0.3 0.5 0.5 depth (mm)Measured 0.01 0.01 0.01 0.01 0.01 0.3 0.2 wedth (mm) Degree of Good Verygood Very good Good Bad Bad Bad opening Invisibility Very good Very goodGood Very good Very good Fair Fair Capability to Good Very good Verygood Good Bad Good Good measure film thickness Capability of Good Verygood Very good Good Fair Good Good development

INDUSTRIAL APPLICABILITY

According to a vehicle upholstery member having an air bag door of thepresent invention, it has been possible to provide a vehicle upholsterymember having an air bag door, in which a portion of the back surface ofa skin made of a thermosetting resin or a thermoplastic resincorresponding to the portion where the vehicle air bag door is installedis formed with a break-scheduled line that is not so deep as to reachthe surface of the skin and adapted to assume a substantially V-shapedgroove when the skin is bent with its back surface convexed, therebyallowing for easy measurement of the depth of the break-scheduled linewith an optical film thickness measurement device and excellentinvisibility.

Moreover, according to a method of producing a vehicle upholstery memberhaving an air bag door of the present invention, it has been possible toefficiently provide a vehicle upholstery member having an air bag door,in which a portion corresponding to the portion where the vehicle airbag door is installed is provided with a break-scheduled line and thatis designed for easy measurement of the depth with an optical filmthickness measurement device and that is accurately controlled in agiven depth.

Furthermore, according to a device for producing a vehicle upholsterymember having an air bag door comprising a support base forsubstantially flatly mounting a skin thereon, a cutting blade forforming a break-scheduled line in the skin, and measuring means formeasuring the depth of the break-scheduled line or the thickness of theremaining portion, wherein the measuring means is used to measure thedepth of the break-scheduled line or the thickness of the remainingportion with the incision of the break-scheduled line opened, it hasbeen possible to provide a vehicle upholstery member having an air bag,in which a portion corresponding to the portion where the vehicle airbag is installed is provided with the break-scheduled line that isaccurately controlled in a given depth.

1. A method of producing a vehicle upholstery member having an air bagdoor equipped with a fabricated skin, comprising the following steps (A)to (C) in order: (A) substantially flatly mounting the skin on a supportbase; (B) forming a break-scheduled line that is not so deep as to reacha front surface of the skin with a cutting blade; and (C) measuring adepth of the break-scheduled line or a thickness of a remaining portionof the skin where the break-scheduled line is formed with an incision ofthe break-scheduled line opened, wherein a protrusion arranged in thesupport base is moved up to a given height and pressed upward againstthe skin to therby open the incision of the break-scheduled line.
 2. Themethod producing the vehicle upholstery member having the air bag dooraccording to claim 1, wherein the skin is aspirated from the frontsurface side and fixed on the support base.
 3. The method of producingthe vehicle upholstery member having the air bag door according to claim1, wherein, at the step (B), the break-scheduled line is formed whiledetecting an altitude of an edge of the cutting blade from a surface ofthe support base.
 4. The method of producing the vehicle upholsterymember having the air bag door according to claim 1, further comprisingthe step of detecting a state of a damage of the cutting blade prior tothe step (B).
 5. The method of producing the vehicle upholstery memberhaving the air bag door according to claim 1, wherein, at the step (C),the depth of the break-scheduled line or the thickness of the remainingportion of the skin where the break-scheduled line is formed is measuredwith an optical film thickness measurement device.
 6. A method ofproducing a vehicle upholstery member having an air bag door equippedwith a fabricated skin, comprising the following steps (a) to (c): (a)partially or entirely bending the skin with its back surfaced convexed,wherein the skin is mounted on a substrate and pressed with a protrusionarranged in the substrate for bending the skin with its back surfacedconvexed and the protrusion is moved up and pressed upward against theskin; (b) forming a break-scheduled line that is not so deep as to reacha front surface of the skin with a cutting blade; and (c) measuring adepth of the break-scheduled line or a thickness of a remaining portionof the skin where the break-scheduled line is formed with an incision ofthe break-scheduled line opened.
 7. A device for producing a vehicleupholstery member having an air bag door equipped with a fabricatedskin, comprising: a support base for substantially flatly mounting theskin thereon equipped with a protrusion for upward pressing the skin; acutting blade for forming a break-scheduled line in the skin; andmeasuring means for measuring a depth of the break-scheduled line or athickness of a remaining portion of the skin where the break-scheduledline is formed, wherein the protrusion is moved up to a given height andpressed upward against the skin, and wherein the measuring means is usedto measure the depth of the break-scheduled line or the thickness of theremaining portion of the skin where the break-scheduled line is formed,with an incision of the break-scheduled line opened.
 8. The device forproducing the vehicle upholstery member having the air bag dooraccording to claim 7, wherein the protrusion is constructed of one ormore linear objects or curved objects.
 9. The device for producing thevehicle upholstery member having the air bag door according to claim 7,further comprising position-detecting means for detecting an altitude ofan edge of the cutting blade from a surface of the support base.
 10. Thedevice for producing the vehicle upholstery member having the air bagdoor according to claim 7, further comprising state-detecting means fordetecting a state of the damage of the cutting blade.
 11. The device forproducing the vehicle upholstery member having the air bag according toclaim 7, wherein the support base is provided with a suction portion forfixing the skin therein.